The present invention relates to a therapeutic agent for glaucoma which comprises administering 2-phenyl-3-oxo-2H-1,4-benzothiazine derivative by systemic and/or topical route.
Glaucoma is an intractable eye disease caused by an elevation of intraocular pressure with various factors and a patient of glaucoma has a risk of losing his eyesight, and various medical treatments have been proposed. U.S. Pat. No. 4,786,635 discloses the use of 2-phenyl-3-oxo-2H-1,4-benzothiazine derivatives. It is described therein that these compounds have a unique structure and are useful as a therapeutic agent for circulatory diseases, since they have a calcium antagonistic effect and a blood platelet coagulation-inhibiting effect. However, any effect of these compounds on eyes has not been known.
The present inventors decided to make investigations on other effects of these compounds particularly in the ophthalmologic field.